Revealing the Combined Nanoconfinement Effect by Soft and Stiff Inclusions in PMMA/Silica CO₂ Blown Foams

Abstract

This study shows the importance of nanoparticle (NP) spatial arrangement on the nucleation, morphology, and properties of nanocomposite foams. It probes CO2 blown PMMA with three types of nanosilica structures with exactly the same chemical composition: aggregates, chain bound clusters, and individually dispersed NPs. A systematic but nontrivial scaling of morphology, glass transition temperature, static and impact mechanical properties, and thermal conductivity is discussed with special regard to the combined nanoconfinement by soft and stiff inclusions. The presented results suggest a limited potential of simultaneous toughening by nanoreinforcement and shear banding, which can draw significant implications for both the fundamental science and industrial practice dealing with nanoreinforced cellular materials.

Effect of the nanoparticles on the morphology and mechanical performance of thermally blown 3D printed HIPS foams

“…The 3D printing can organize the structure at the macro scale and build the bodies by the addition of material in a bottom‐up approach 6 . Consequently, the inner structure of the printouts could be tuned by a top‐down foaming process with an admirable precision, especially in the presence of NPs which serve as nucleation centers, facilitating more homogeneous and finer structure of the foam 7 . Certain NPs could also reinforce the cell walls which prevents coalescence of the growing pores and provides a further contribution to the mechanical robustness at the micro‐scale level 8–10 …”

“…6 Consequently, the inner structure of the printouts could be tuned by a top-down foaming process with an admirable precision, especially in the presence of NPs which serve as nucleation centers, facilitating more homogeneous and finer structure of the foam. 7 Certain NPs could also reinforce the cell walls which prevents coalescence of the growing pores and provides a further contribution to the mechanical robustness at the micro-scale level. [8][9][10] The breakthrough in the fabrication of complex shapes was recently seen because of the 3D printing which uses a programmable addition of voxels, that is, the smallest volume of a controlled size and shape, to build up larger objects.…”

Frontally polymerized foams: thermodynamic and kinetical aspects of front hindrance by particles

“…23 Finally, nanocomposite foams represent a broad category of lightweight materials. NPs and other nanofillers are often used to control the foam morphology, reducing the cell size through enhanced cell nucleation [24][25][26] or introducing functional properties such as electric conductivity. 27 However, NPs also have a complex effect on mechanical deformation and fracture due to the combined nanoconfinement effect from soft and stiff inclusions represented by the voids and the nanoparticles.…”

“…27 However, NPs also have a complex effect on mechanical deformation and fracture due to the combined nanoconfinement effect from soft and stiff inclusions represented by the voids and the nanoparticles. 26 In the only previous attempt known to the authors, the FP has been deployed to fabricate polymer foams by including a physical blowing agent into a standard FP formulation. 5 The morphology of FP foams was controlled by the concentration and type of the blowing agent.…”

Investigation on Various Ceramic Nanoparticles Reinforced Aluminum Matrix Composites via Accumulative Roll Bonding and Cryorolling

“…Furthermore, the presence of nanoparticles or particle/matrix interfaces increases the potential for suppressing crack initiation and propagation, leading to advantageous improvements in the mechanical properties of the composites. [ 18,19 ] Thus, it is expected that utilizing nanoparticles as reinforcement will result in high‐performance nanocomposites.…”